Postdoctoral Research Fellow PRI - Michigan State University Lansing, Michigan
Body of Abstract: Global climate change imposes rapid alterations in local environmental conditions and contributes significantly to prolonged ecosystem-level changes. In addition to influencing plant health, these environmental changes alter the composition of the plant microbiota. Importantly, plant microbiomes have been associated with nutrient uptake, disease resistance, and abiotic stress tolerance. Additionally, assembly of the root microbiome is mediated by the phytohormone salicylic acid. In this work, drought is used as an abiotic stress elicitor to explore the broader impacts of water availability on plant resilience by observing both plant physiological measurements and induced shifts in the assembled root microbiome. The focus of this work aims to define the convergence of drought tolerance with plant-associated microbial community composition and the subsequent role of the physiological and immune response of the plant on microbiome assembly during drought. A 40-member bacterial synthetic community (SC40) representative of bacterial taxa commonly found in natural and agricultural soils was used to inoculate wild-type Arabidopsis and mutant lines associated with salicylic acid biosynthesis/signaling (sid2, pad4, and cpr1) and abiotic stress response (ndr1 and erd4). Sterile seedlings for each of the six lines were inoculated with SC40 and grown for two weeks before induction of drought conditions. At harvest, fresh root and shoot weight, along with relative water content (RWC), were obtained as a proxy of plant health. While uninoculated plants behaved similarly during drought regardless of genotype, the presence of SC40 appears to play a role in drought tolerance. Root microbiomes will be profiled with 16S rRNA amplicon sequencing to identify microbiome assembly patterns across genotype and environmental conditions. More work is necessary to identify specific mechanisms, but these preliminary findings provide important stepping stones for understanding the crosstalk between the host physiological response and the resulting microbiome assembly during drought.